Human Cryptosporidiosis in Immunocompetent and Immunodeficient Persons

Abstract
Infection with cryptosporidium occurred in 12 immunocompetent persons who had direct contact with the feces of infected calves during three unrelated outbreaks of calf cryptosporidiosis. Nine of the twelve subjects had diarrhea and abdominal cramps that lasted 1 to 10 days. Infections were diagnosed and monitored by detection of oocysts in feces, with a modified Sheather's flotation technique and phase-contrast microscopy. Oocysts of cryptosporidium were isolated from calves but not from other animals with which these subjects had been in contact. Oocysts of cryptosporidium were also detected during repeated examinations of feces from two immunodeficient patients with persistent cryptosporidiosis. An apparently identical infection was transmitted to calves and mice, using oocysts from infected calves and human beings. Oocysts from an immunodeficient person also produced infections in kittens, puppies, and goats.